The invention relates to a hearing aid comprising a housing with at least one acoustic inlet opening and at least one acoustic outlet opening, where the housing contains a microphone, an amplifier in connection with the microphone, a receiver in connection with the amplifier and a battery for power supply, where the housing is provided with a hook for transmittal of acoustic signals from the acoustic outlet opening into the ear of the user, the housing comprising two connectable and detachable parts.
A hearing aid of this type is well known within the art of hearing aids as a so-called BTE hearing aid. Normally the two parts of the housing are maintained in a mutually fixed position by means of separate fastening means such as screws or the like. The result of this is that the material in the housing parts at the area of fastening is significantly stressed, which may lead to breakage of the material in these areas. This is especially the case when a hearing aid is dropped on a hard surface, which happens occasionally. In this situation the already stressed housing material may break more easily if not dimensioned for the additional stress. This means that the hearing aid housing may comprise more housing material than necessary for resisting the impact applied when the hearing aid is dropped. More material means more weight and hence an increased discomfort for the user. Furthermore the assembly by means of such housing parts by means of fastening means such as screws is a delicate and time-consuming process due to the very small sizes of the fastening means.
CH 673364 discloses a hearing aid with a housing comprising two parts, which are mutually interconnected by means of one or more clamps. This construction is difficult to handle due to the very small size of the clamps. The clamps furthermore must provide a significant spring force in order to maintain the position of the housing parts, which makes the mounting of these extremely difficult.
CH 687897 discloses a similar construction, presenting similar disadvantages.
EP 416155 discloses a hearing aid with a housing comprising two parts, which are mutually interconnected by means of a snap connection. The construction is likely to vibrate and the resonance of such vibration will be very disturbing for the user of the hearing aid.
U.S. Pat. No, 5,062,138 discloses a hearing aid with a housing comprising two parts, which are mutually interconnected by means of a snap connection. The construction is likely to vibrate and the resonance of such vibration will be very disturbing for the user of the hearing aid.
The objective of the present invention is to provide a hearing aid which may be assembled without inflicting stress on the housing parts, which may be assembled in a less time consuming manner i.e. which is easier to assemble and which is less prone to resonate due to vibrations in the housing parts.
According to the invention this is obtained by a hearing aid of the type mentioned in the introductory part of the description and which is characterized in that means are provided on each housing part for mutually snap locking the parts.
Hereby the fastening elements may be omitted and the stress impact of these is no longer present. Hence the housing may be dimensioned with a smaller strength and still resist impact if the user accidentally drops the hearing aid. The assembling of the hearing aid is furthermore significantly facilitated.
In a preferred embodiment a protruding element is provided in one of the two detachable parts, preferably in the vicinity of the acoustic inlet opening, and an opening is provided in the other of the two detachable parts and being adapted to receive the protruding element. There may be more acoustic inlet openings, preferably two, where in connection with each of these a protruding element may be provided. The second detachable part has a corresponding number of openings for receiving the protruding element. A further possibility comprises providing a protruding wall around each opening.
In a further preferred embodiment one of the housing parts comprises an arm having a barb is provided at one end of one of the two detachable parts.
In a still further preferred embodiment the housing parts are separated along their sides and that mutually cooperating guide means are provided at the side edges of the respective elements.
In another preferred embodiment the housing parts are separated along their sides and stays are provided at the sides of one of the housing parts and that corresponding holes are provided in the other housing part.